The present invention relates to automated distribution systems for storing and retrieving articles.
Many modern production and warehousing facilities require the storage and retrieval of thousands of inventoried goods. The goods may be stored in containers due to their size or delicate construction. Therefore, storage requires loading the containers and delivering them to a known location where subsequently they can be retrieved as necessary. When required, the desired items must be retrieved from their respective positions. An efficient storage operation includes the ability to store and retrieve a wide variety of goods and to dispose of the retrieved items rapidly and effectively. A wide variety of warehousing and distribution systems have been proposed to reduce the labor required in warehousing operations.
Certain storage and retrieval systems use large multi-level fixed storage shelves in combination with an extractor or picking mechanism that must travel to a particular shelf to pick a desired inventory item. For example, a mobile unit may traverse along a series of stationary vertical racks. The mobile unit is equipped with mechanisms for loading and unloading the vertically based storage racks. Such systems have several drawbacks. Initially, they are limited to a small number of insertion or extraction transactions each time the extractor is operated because the picking mechanism must be moved after each insertion or extraction operation. Additionally, such systems traditionally have fixed locations for storing each type of goods received within the warehouse. This prevents efficient space utilization since the fixed location occupies the same amount of space regardless of the number of stock units for a particular inventoried item. Therefore, such systems can waste valuable building space.
An improved automated storage and retrieval system having a storage carousel that can remain in continuous motion while containers are inserted onto or extracted from the carousel storage racks previously has been developed. That system is the subject of several U.S. patents, including U.S. Pat. Nos. 5,556,247; 5,282,712; 5,090,863; and 4,983,091, which are assigned to the assignee of the subject application and are incorporated herein by reference.
There also is a need for a rapid storage or staging and retrieval system which readily can be adapted for efficient use with articles of varying or different sizes. This system should have a high transaction rate, which is the speed at which container insertion and extraction operations occur. It should also be capable of installation, for instance, in an existing warehousing facility with minimal impact on other facility resources, such as sources of electrical power and compressed air.